METHOD OF PRODUCING POLYVINYL ALCOHOL RESIN, AND POLYVINYL ALCOHOL RESIN OBTAINED THEREBY
申请人:Japan Vam & Poval Co., Ltd.
公开号:EP3059266A1
公开(公告)日:2016-08-24
Provided are a method for producing a polyvinyl alcohol resin which is highly transparent in the form of an aqueous solution, has a good appearance when formed into a film or an aqueous gel, and improves ink acceptability and color appearance and exhibits water resistance when used for a thermal recording material or an ink-jet recording material; and a polyvinyl alcohol resin obtained by the method. In particular, provided is a method for producing a polyvinyl alcohol resin, comprising the steps of copolymerizing an aliphatic vinyl ester (A) with diacetone acrylamide (B), at least a part of which diacetone acrylamide (B) is added at a later stage, in the presence of a polymerization catalyst in an alcohol solvent, so that the ratio (a)/(b) of the polymerization yield at the end of the polymerization (a) to the polymerization yield at the end of the later addition (b) of diacetone acrylamide (B) is in the range of 1.01 to 1.10, and saponifying the resulting copolymer.
本发明提供了一种聚乙烯醇树脂的生产方法,该聚乙烯醇树脂在水溶液形式下具有高透明性,在形成薄膜或水性凝胶时具有良好的外观,并且在用于热敏记录材料或喷墨记录材料时可改善油墨的可接受性和颜色外观,并具有防水性;还提供了一种通过该方法获得的聚乙烯醇树脂。具体而言,本发明提供了一种生产聚乙烯醇树脂的方法,包括以下步骤:脂肪族乙烯基酯 (A)与双丙酮丙烯酰胺(B)共聚,其中至少一部分双丙酮丙烯酰胺(B)在稍后阶段加入、在醇溶剂中,在聚合催化剂存在下,使聚合结束时的聚合产率 (a)/(b) 与后期添加二丙酮丙烯酰胺 (B) 时的聚合产率 (b) 之比范围在 1.01 至 1.10,并对所得共聚物进行皂化。